Provided is a method of magnetic transfer. The method includes initially DC-magnetizing a transfer-recipient disc in a circumferential direction, by applying a magnetic field to the transfer-recipient disc in the circumferential direction thereof bringing initially DC-magnetized transfer-recipient disc and a master disc into close contact with each other, on the top side of the master disc a magnetic layer including a great number of protrusions that configure a magnetic pattern being formed; and executing magnetic transfer in such a way that a magnetic-field generation device is provided, and that, when a magnetic field is applied in a circumferential direction to the transfer-recipient disc and the master disc, transfer of the magnetic pattern of the master disc onto the transfer-recipient disc occurs.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A magnetic-transfer method comprising the steps of: initially DC-magnetizing a transfer-recipient disc in a circumferential direction, by applying a magnetic field to the transfer-recipient disc in the circumferential direction thereof; bringing initially DC-magnetized transfer-recipient disc and a master disc into close contact with each other, on the top side of the master disc a magnetic layer including a great number of protrusions that configure a magnetic pattern being formed, ratio t/b of thickness t of the magnetic layer to circumferential length b of the protrusion being from 0.5 to 4.0; and executing magnetic transfer in such a way that a magnetic-field generation device is provided, and that, when a magnetic field is applied in a circumferential direction to the transfer-recipient disc and the master disc so as to transfer the magnetic pattern of the master disc onto the transfer-recipient disc, ratio Hv/Hh of the strength Hv of a magnetic field, of the circumferential magnetic field, that is vertical to the top side of the transfer-recipient disc, to the strength Hh of a magnetic field, of the circumferential magnetic field, that is in parallel with the top side of the transfer-recipient disc, is made equal to or smaller than 0.629-0.0571×t/b.
2. The magnetic-transfer method according to claim 1 , wherein magnetic transfer is executed while moving the transfer-recipient disc and the master disc that are closely contacted to each other, relatively to the magnetic-field generation device.
3. The magnetic-transfer method according to claim 2 , wherein, after the circumferential magnetic field is applied, once or more times in the circumferential direction, to the transfer-recipient disc and the master disc that are closely contacted to each other, the strength of circumferential magnetic field is decreased down to a predetermined value, and then relative movement, to the magnetic-field generation device, of the transfer-recipient disc and the master disc that are closely contacted to each other is halted.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
October 13, 2005
October 21, 2008
Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.